BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C146E,C146F; Open Circuit in ABS Solenoid Relay Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001G7AG
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C146E,C146F; Open Circuit in ABS Solenoid Relay Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

C146E

Open Circuit in ABS Solenoid Relay Circuit

DTC

C146F

Short Circuit in ABS Solenoid Relay Circuit

DESCRIPTION

The ABS solenoid relay built into the skid control ECU (brake booster with master cylinder assembly) supplies power to the holding solenoid and reduction solenoid.

The ABS solenoid relay is operated 1.5 seconds after the power switch is turned on (IG), and is turned off if an open or short in the ABS solenoid is detected during self-diagnosis when the vehicle starts driving.

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	MIL	Note
C146E	Open Circuit in ABS Solenoid Relay Circuit	1135	Either of the following is detected: When the power switch is on (READY): When the IG1 terminal voltage is 9.5 V or more and operation of the ABS solenoid relay is requested, the ABS solenoid relay does not operate (+BS terminal voltage is less than 3.5 V) for 0.2 seconds or more. When the power switch is off: When operation of the ABS solenoid relay is requested, the ABS solenoid relay does not operate (+BS terminal voltage is less than 3.5 V) for 0.2 seconds or more.	Wire harness or connector Skid control ECU (brake booster with master cylinder assembly)	Comes on	INF Code 1135: SAE Code C146E ABS DTC
C146F	Short Circuit in ABS Solenoid Relay Circuit	1136	When operation of the ABS solenoid relay is not requested, the ABS solenoid relay operates (+BS terminal voltage is 3.5 V or more) for 4.5 seconds or more.	Skid control ECU (brake booster with master cylinder assembly)	Comes on	INF Code 1136: SAE Code C146F ABS DTC

MONITOR DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) monitors the voltage of the ABS solenoid.

When the ABS solenoid relay is instructed to be on and the voltage of the ABS solenoid is within the range of an open circuit malfunction, or when the ABS solenoid relay is instructed to be off and the voltage of the ABS solenoid is within the range of a short circuit malfunction, an open circuit or short circuit is judged respectively and the MIL is illuminated and a DTC is stored.

MONITOR STRATEGY

Related DTCs	C146E (Case 1): ABS solenoid power supply relay circuit low C146E (Case 2): ABS solenoid power supply relay circuit low C146F (Case 1): ABS solenoid power supply relay circuit high C146F (Case 2): ABS solenoid power supply relay circuit high
Required Sensors/Components(Main)	Brake actuator assembly
Required Sensors/Components(Related)	Skid control ECU (brake booster with master cylinder assembly)
Frequency of Operation	Continuous: C146E (Case 1), C146F (Case 1) During initial checking: C146E (Case 2), C146F (Case 2)
Duration	0.2 seconds: C146E (Case 1 and 2) 2 seconds: C146F (Case 2) 4.5 seconds: C146F (Case 1)
MIL Operation	Immediately
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

All

Monitor runs whenever the following DTCs are not stored

None

C146E (Case 1)

All of the following conditions are met	A, B and C
A. Skid control ECU (brake booster with master cylinder assembly) state	Normal
B. Command to ABS solenoid power supply relay	On
C. Either of the following conditions is met	a or b
a. Both of the following conditions are met	-
Power switch	Off
Brake system voltage 1 (VM1)	Higher than 6.92 V
b. All of the following conditions are met	-
Power switch	On (READY)
Brake system voltage 1 (VM1)	Higher than 6.92 V
IG1 voltage	Higher than 9.54 V

C146E (Case 2)

All of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Initial check
Command to ABS solenoid power supply relay	On
Brake system voltage 1 (VM1)	Higher than 6.92 V

C146F (Case 1)

Both of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Normal
Command to ABS solenoid power supply relay	Off

C146F (Case 2)

Both of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Initial check
Command to ABS solenoid power supply relay	Off

TYPICAL MALFUNCTION THRESHOLDS

C146E (Case 1 and 2)

Power supply for ABS solenoid

Less than 3.5 V

C146F (Case 1 and 2)

Power supply for ABS solenoid

3.5 V or more

COMPONENT OPERATING RANGE

C146E

All of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Normal
Command to ABS solenoid power supply relay	On
Power supply for ABS solenoid	3.5 V or more

C146F (Case 1)

All of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Normal
Command to ABS solenoid power supply relay	Off
Power supply for ABS solenoid	Less than 3.5 V

C146F (Case 2)

All of the following conditions are met	-
Skid control ECU (brake booster with master cylinder assembly) state	Initial check
Command to ABS solenoid power supply relay	Off
Power supply for ABS solenoid	Less than 3.5 V

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off.
Turn the power switch on (IG).
Turn the Techstream on.
Wait 4.5 seconds.
Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
Read the DTCs.
HINT:
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
If the DTCs are not output, perform a universal trip and check for permanent DTCs.
Click here
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTCs are output, the system is normal.

WIRING DIAGRAM

Refer to DTCs C1352, C1353, C1354, C1355, C1356, C1357, C1358 and C1359.

Click here

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

When DTCs C1241 and/or C1417 are output together with C146E and/or C146F, inspect and repair the trouble areas indicated by C1241 and/or C1417 first.

for C1241: Click here

for C1417: Click here

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (BS TERMINAL)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a	Front view of wire harness connector (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the A48 skid control ECU (brake booster with master cylinder assembly) connector.

OK:

No deformation or corrosion.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A48-52 (BS) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)

2.	CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(b) Disconnect the A113 brake actuator assembly connector.

OK:

No deformation or corrosion.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A48-14 (+BS) - A113-5 (+BS)	Always	Below 1 Ω
A48-14 (+BS) or A113-5 (+BS) - Body ground	Always	10 kΩ or higher
A48-48 (SFRH) - A113-31 (SFRH)	Always	Below 1 Ω
A48-48 (SFRH) or A113-31 (SFRH) - Body ground	Always	10 kΩ or higher
A48-49 (SFLH) - A113-28 (SFLH)	Always	Below 1 Ω
A48-49 (SFLH) or A113-28 (SFLH) - Body ground	Always	10 kΩ or higher
A48-50 (SRRH) - A113-29 (SRRH)	Always	Below 1 Ω
A48-50 (SRRH) or A113-29 (SRRH) - Body ground	Always	10 kΩ or higher
A48-51 (SRLH) - A113-30 (SRLH)	Always	Below 1 Ω
A48-51 (SRLH) or A113-30 (SRLH) - Body ground	Always	10 kΩ or higher
A48-44 (SFRR) - A113-15 (SFRR)	Always	Below 1 Ω
A48-44 (SFRR) or A113-15 (SFRR) - Body ground	Always	10 kΩ or higher
A48-45 (SFLR) - A113-18 (SFLR)	Always	Below 1 Ω
A48-45 (SFLR) or A113-18 (SFLR) - Body ground	Always	10 kΩ or higher
A48-46 (SRRR) - A113-17 (SRRR)	Always	Below 1 Ω
A48-46 (SRRR) or A113-17 (SRRR) - Body ground	Always	10 kΩ or higher
A48-47 (SRLR) - A113-16 (SRLR)	Always	Below 1 Ω
A48-47 (SRLR) or A113-16 (SRLR) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	RECONFIRM DTC

(a) Reconnect the A48 skid control ECU (brake booster with master cylinder assembly) connector.

(b) Reconnect the A113 brake actuator assembly connector.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

(d) Turn the power switch off.

(e) Turn the power switch on (READY).

(f) Perform a road test.

(g) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C146E and C146F are not output.	A
DTCs C146E and/or C146F are output.	B

HINT:

If a speed signal of 20 km/h (12 mph) or more is sent to the skid control ECU (brake booster with master cylinder assembly) with the power switch on (IG) and the stop light switch assembly off, the ECU performs self-diagnosis of the motor and solenoid circuits.
If the normal system code is output (no DTCs are output), slightly jiggle the connectors, wire harness, and fuses of the skid control ECU (brake booster with master cylinder assembly).
If any DTCs are output while jiggling a connector or wire harness from the brake booster with master cylinder assembly, inspect and repair the connector or wire harness.
The DTCs were probably output due to a bad connection of the connector terminal.

USE SIMULATION METHOD TO CHECK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY